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PatentedSept. 1, 1925 UNITED STATES ;VP ATENTY f mocns's roa surname rnon ALLOYS.

No Drawing;

Application filed February 2,, 1921. Serial m. 441,819.

(Gunman unnaa 'rnr. rnovlsrons or THE ACT qr uaacn a, 1921,41 sum. n, 1913. p H

.To all whom it may concern! Be it known that'I FRITZ GREINER, citizen of the German liepublic, residing at Cannstatt-on-the-Neckar, Germany, have in- 6 vented new and useful Improvements in Processes for SmeltingIron Alloys and on which foreign applications have been filed in the following countries: Germany, filed November 19th, 1917,, Patent No. 315

- 1 0 323, Februar'y 12th, 1919, Patent No. 322,'-'

947; October 2nd,-1919, Qctober3rd, 1919, and October 24th, 1919, not yet, patented; Austria, filed January 23rd,,1919, PatentNo.

' 83,531, April.16th,,1919, PatentNo. 83,532;

1 Bohemia, filed January 25th, 1919, Patent No. 4,312, May 31st, 1919, Patent No. 4,971 Hungary, filed January 25th, 1919, Patent No, 78,554, May 16th, 1919, Patent ,No. 80,- 476; Switzerland, filed January 24th, 1919,

20 Patent No. 82,086, April 22nd, 1919, Patent -No. 88,324,, July 25th. 1919, Patent No.'

84,089; Belgium, filed May 2nd, 1919, Patent No. 280,175 France, filed'May 6th, 1919, Patent No. 524,446; Italy, filed May 28th,

25 1919, Patent No, 539/1665; fHolland, filed December 1st, 1919, Patent No. 7,489; Spain,

filed November 10th, '1919, Patent'71,460;*

Finland, filed September29th, 1919, Patent No. 8,035; Denmark filed May -6th, 1919,

30 Patent No. 29,430;

1919, Patent No; 23,783; and Sweden, filed April 28th, 1919, Patent No. 53,532, ofwhich the following is a specification'.

The present invention relates to a ,process 7 for protecting'iron alloyed with a high percentageof elements havin a great afiinity to oxygen, as for instance si icon, manganese, phosphorus or like ingredients, against burning when smelted. When iron is smelted in 40 a cupola or hearth furnace with one .of their.

aforementioned substances alarge amount of I, the admixtures ,is always lost because the oxygen contai'nrexj in the furnace gases oxidizes the said "valuable partsfof the alloy and converts-them into oxides that are worthless as far as the smelting process is concerned. Thus it is just the: more valuable parts of the alloy thatvare' lost'because their chemical aflinity to the oily en of the 5 air isconsiderably greater thant at of'theiron. Hencethe ingredients alf'e attacked in a much greater degree thanthe iron so that the proportion between the parts of the alloy changes greatly and in a'degree which can Norway, filed May 12th,

containing a definite percentage of silicon,

manganese, phosphorus or the like. a 05 The object of the present lnvention is to 7 remove these evils and it is accomplished by enveloping the alloy of'which I cite ferrosilicon as an example, in the form of fraginents or powder, or in'the form of a mixture of fragments and powder with a fireproof coating which protects the alloy during the smelting process, against the action of the oxygen of the air. The inventor applies the term fire-proof to any inert mineral matter the melting point of which is so high that it does not melt or drip away at or slightly above the temperature constit'uting the melting. point of the alloy. The fire-proof substance to be considered so first in this connection is lime, pure or with admixtures of any material'not affecting the s fire-proofness of the lime; or any calcareous material of the same properties furnishing lime in the course of the reaction. The pro- 'portion of the admixture should-be as small as possible. Lime' is particularlygadapted for the saidpurpose because apart from its high meltingipolnt it must be added in any case to bind the sulphur andeifect the'formation of slags. Large :pieces of metal then onlyneed to be dipped into. the paste of calcareous material which will soon form a hard coat; Such substances as tar for example do not form suitable enveloping agents because they would immediately burn away in the furnace and would therefore be incapable of protecting the alloys against the action of the hot air in the furnace. Hence tar can only be used as a binding agent for powdered lime.

Now, in enveloping the said 'alloys in the above described manner it is advantageous W to also adopt a briquetting process, especially if the material to be handled is 'fragmentaryor pulverized, or; of different degrees of coarseness. The preferable form,

of lime for the briquetting of the alloys is J that contained in Portland cement; I use .1. The process of smelting ferro-alloys this mixture because it has a high meltin point, contains much lime, and is a good greater affinity to oxygen than iron has, said binding agent. The fragmentary or pulprocess comprising reducing the ferro-alloy verized metalsto be dealt with are molded to pieces of convenient size and coating said with the aid of Portland cement into the pieces with an inert material, having asha'pes usually made with cement, and gravel higher melting point than the ferro-alloy, or sand. If lime instead of Portland cement before charging them into the smelting is to be used for briquetting, tar should be furnace. added to the lime as a binding agent. Al- 2. The process of smelting ferro-alloys though the tar will be burnt away the having constituent parts with a considerably briquets do not fall apart when heated up greater affinity to oxygen than iron has, said to the melting pointso that the oxygen conprocess comprising shaping pieces of the tained in the furnace gases does not harm ferro-alloy of various degrees of fineness their contents. with an inert, fire resistant mateiial, having I know that the solution of the problem of a higher melting point than the ferro-alloy, protecting the constituents of iron alloys, into a form ofconvenient size suitable for like silicon, manganese, phosphorus etc., charging same into the smelting furnace. which have agreat affinity to oxygen, dur- 3. The process of smelting ferro-alloys having constituent parts with a considerably ing smelting operations, has been sought having constituent parts with great affinity Y for some time. Attempts in this direction to oxygen, said process comprising reducing were made by forming cakes of for instance the ferro-alloy to pieces of convenientsize ferro-silicon merely by pressing together and coating said pieces with calcareous mairon or steel fragments such as filings or terial before charging them into the smelting turnings under a high pressure, or by workfurnace. V

ing the fragmentary metal up into shapes 4. The process of smelting ferro-alloys with the aid of coal tar. But these two having constituent parts with greatafiinity processes have not been proved to be advanto oxygen, said process comprising reducing tageous for in the case of the former there the ferro-alloy to pieces of convenient size was no enveloping coating that could have and coating said pieces with lime provided protected the ferro-silicon. against overwith a binding agent before charging them heating in the furnace. In the second procinto the smelting fiirnace. ess a coating was present at first, but it was -5. The process of smelting ferro-alloy's useless, because it burned away immediately, having constituent parts with great affinity after it was placed in the furnace. To use to oxygen, said process comprising reducing a fire-proof coa-t, as for instance, cement as the ferro-alloy to pieces of convenient size .a binding agent instead of coal-tar was not and coating said pieces with lime before by any means obvious because, under ordicharging them into the smelting furnace. nary conditions cement loses its chemically 6. The process of smelting ferro-silicon, bound water at temperatures'of 500 to 600 said process comprising reducing the ferrocentigrades and crumbles to powder. The silicon to pieces of convenient size and coatcause of this new and unexpected behaviour ing said pieces with lime before charging of cement is probably a secondary reaction them into the smelting furnace. of the lime with one part or other of the ferro-alloy. I said process comprising reducing the ferro- Another important point to be noted is silicon to pieces of convenient size'and coatthat in cases in whichthe iron alloy to be ing said pieces with Portland cement before worked is in large pieces, I prefer to break I charging them into the smelting furnace. these pieces in any suitable way into pieces 8. The process of'smelting ferro-silicon v of the size of hazelnuts. These pieces are said process comprising shaping pieces of 7. The process of smelting ferro-silicon,

then worked together with any smaller pieces that might be present, or with powdered ferro-silicon, in the manner already described. i I

Having now particularly described and ascertained the nature of my said invention, and'in what manner the same is to be performed, I declare that what I claim is;

ferro-silicon of various degrees of fineness with Portland cement into a form of convenient shape suitable for charging into the smelting furnace,

In testimony whereof I have signed my name to this specification.

. J FRITZ GREINER. 

